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Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young's modulus and Poisson's coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions: DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.

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OBJECTIVES: To synthesise the dentoalveolar, periodontal and skeletal changes that occur when using maxillary expansion techniques assisted by temporary anchorage devices compared to conventional protocols. METHODS: Five databases and grey literature were consulted, up to December 2023, focusing on intervention designs and excluding other type of studies. The quality assessment was conducted by using the adaptation for orthodontics of the CONSORT statement, the guidelines for reporting non-randomised studies, the RoB-2 tool, and the ROBINS-I tool. A descriptive summary and meta-analysis using RevMan 5.4 were performed. RESULTS: Nine clinical trials were included (n=377 patients, mean age 13.2±0.6) with a diagnosis of transverse maxillary deficiency. The analysed studies showed qualitative dentoalveolar and periodontal changes after expansion, which were greater on the maxillary first premolars in tooth-borne appliances. Meta-analyses for some effects were included from two studies (n=64); patients who used tooth-borne appliances had greater effects of buccal intercoronal width between the premolars with statistically significant differences (Std Mean difference 2.34; 95% CI: 0.04-4.65 p=0.05). Conversely, those patients who used bone-borne or hybrid appliances had greater effects of buccal intercoronal width between molars with statistically significant differences (Std Mean difference -0.64; 95% CI: -1.38-0.10; p=0.09). CONCLUSIONS: According to the studies analysed, all measurements increased in the intervention groups after expansion. Quantitative analyses show different findings at dentoalveolar level when tooth-borne, bone-borne or hybrid appliances are considered. Nevertheless, the results should be taken with caution due to the heterogeneity of the studies. The protocol was registered at PROSPERO (CRD42021283170), with no funding to report.

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ABSTRACT Objective: This study aimed to compare the influence of four different maxillary removable orthodontic retainers on speech. Material and Methods: Eligibility criteria for sample selection were: 20-40-year subjects with acceptable occlusion, native speakers of Portuguese. The volunteers (n=21) were divided in four groups randomized with a 1:1:1:1 allocation ratio. The four groups used, in random order, the four types of retainers full-time for 21 days each, with a washout period of 7-days. The removable maxillary retainers were: conventional wraparound, wraparound with an anterior hole, U-shaped wraparound, and thermoplastic retainer. Three volunteers were excluded. The final sample comprised 18 subjects (11 male; 7 female) with mean age of 27.08 years (SD=4.65). The speech evaluation was performed in vocal excerpts recordings made before, immediately after, and 21 days after the installation of each retainer, with auditory-perceptual and acoustic analysis of formant frequencies F1 and F2 of the vowels. Repeated measures ANOVA and Friedman with Tukey tests were used for statistical comparison. Results: Speech changes increased immediately after conventional wraparound and thermoplastic retainer installation, and reduced after 21 days, but not to normal levels. However, this increase was statistically significant only for the wraparound with anterior hole and the thermoplastic retainer. Formant frequencies of vowels were altered at initial time, and the changes remained in conventional, U-shaped and thermoplastic appliances after three weeks. Conclusions: The thermoplastic retainer was more harmful to the speech than wraparound appliances. The conventional and U-shaped retainers interfered less in speech. The three-week period was not sufficient for speech adaptation.

RESUMO Objetivo: Este estudo teve como objetivo comparar a influência na fala causada por quatro diferentes contenções ortodônticas removíveis superiores. Material e Métodos: Os critérios de elegibilidade para seleção da amostra foram: indivíduos com 20 a 40 anos de idade, com oclusão aceitável, falantes nativos de português. Os voluntários (n=21) foram divididos em quatro grupos, randomizados com proporção de alocação de 1:1:1:1. Os quatro grupos utilizaram os quatro tipos de contenção, em ordem aleatória e em período integral por 21 dias cada, com período de wash-out de sete dias. As contenções superiores removíveis foram: wraparound convencional, wraparound com orifício anterior, wraparound em U e contenção termoplástica. Três voluntários foram excluídos. A amostra final foi composta por 18 indivíduos (11 homens; 7 mulheres) com idade média de 27,08 anos (DP=4,65). A avaliação da fala foi realizada em gravações de trechos vocais, realizadas antes, imediatamente após e 21 dias após a instalação de cada contenção, com análise perceptivo-auditiva e acústica das frequências formantes F1 e F2 das vogais. ANOVA de medidas repetidas e teste de Friedman com Tukey foram utilizados para comparação estatística. Resultados: As alterações de fala aumentaram imediatamente após a instalação das contenções wraparound e termoplástica, e reduziram após 21 dias, mas não para níveis normais. Porém, esse aumento foi estatisticamente significativo apenas para as contenções wraparound com orifício anterior e termoplástica. As frequências dos formantes das vogais foram alteradas no momento inicial e, após três semanas, as alterações se mantiveram com as contenções convencional, em forma de U e termoplástica. Conclusões: A contenção termoplástica foi mais prejudicial à fala do que os aparelhos wraparound. Oswraparounds convencional e em forma de U interferiram menos na fala. O período de três semanas não foi suficiente para adaptação da fala.

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No final da década de 70, ocorreu a introdução da tecnologia de desenho assistido por computador e fabricação assistida por computador (CAD/CAM) na Odontologia. As principais proposições dessa tecnologia seriam automatização do processo manual minimizando as variações ou falhas humanas. Dentre os benefícios do produto citado, destacam-se a possibilidade de individualização dos acessórios de acordo com as necessidades biomecânicas do paciente, personalizando a sua prescrição e o formato da sua base para melhor adaptação ao dente, dando ao ortodontista a possibilidade de alcançar finalizações de tratamentos muito mais precisas. A posição do primeiro molar superior tem grande importância para a clínica ortodôntica. As rotações dos primeiros molares superiores estão presentes na maioria das más oclusões, principalmente na má oclusão de Classe II de Angle Divisão 1, que aumenta o espaço ocupado pelos dentes na arcada dentária. O presente estudo avaliou in vitro o desempenho dos tubos no controle rotacional dos molares superiores. Nesta pesquisa, os tubos foram colados em primeiros molares superiores esquerdos artificiais de resina, aleatoriamente, divididos em quatro grupos, de acordo com o tipo de tubo utilizado e posicionamento de colagem. Os seguintes grupos foram testados: Grupo 1: Tubo cerâmico prototipado, colado na posição central; Grupo 2: Tubo cerâmico prototipado, colado na posição distal; Grupo 3: Tubo simples metálico colado na posição central e Grupo 4:Tubo simples metálico colado na posição distal. Para a execução dos testes, hemiarcadas superiores esquerdas contendo desde o dentes incisivo central superior ao segundo molar superior esquerdo foram obtidas por arquivo STL (Standard Triangle Language) através do software americano Autodesk Meshmixer. Os tubos ortodônticos foram fixados por colagem indireta com cianoacrilato na face vestibular dos dentes. Para a avaliação da eficiência dos tubos ortodônticos na correção da rotação do primeiro molar superior foi necessária a utilização de um simulador eletrônico, com o objetivo de padronizar os testes para todas as amostras pesquisadas. Testes T de student e Mann-Whitney foram aplicados para avaliar diferença estatística entre os resultados obtidos nos grupos. Na posição Central, a média dos pulsos de correção dos tubos cerâmicos prototipados (39.41 pulsos) foi superior à média dos tubos metálicos (27.37 pulsos) (teste T de Student p<0.05). Na posição distal, a média dos pulsos de correção dos tubos cerâmicos prototipados (38.38 pulsos) foi superior à média dos tubos metálicos (18.07 pulsos) (teste de Mann-Whitney, p<0.05). Tubos cerâmicos prototipados obtiveram uma maior intensidade da correção da rotação do molar superior que os tubos metálicos, através da metodologia adotada na presente pesquisa, nas duas situações avaliadas. (AU)

At the end of the 1970s, computer-aided design and computer-aided manufacturing (CAD/CAM) technology was introduced into dentistry. The main propositions of this technology would be the automation of the manual process, minimizing human variations or errors. Among the benefits of the product, the possibility of individualizing the accessories according to the patient's biomechanical needs stands out, customizing their prescription and the shape of their base for better adaptation to the tooth, giving the orthodontist the possibility of achieving complete much more accurate treatments. The position of the upper first molar is of great importance for the orthodontic clinic. Rotations of the upper first molars are present in most malocclusions, especially in Angle Class II Division 1 malocclusion, which increases the space occupied by the teeth in the dental arch. The present study evaluated in vitro the performance of the tubes in the rotational control of upper molars. In this research, the tubes were bonding to artificial resin upper left first molars, randomly, divided into four groups, according to the type of tube used and gluing positioning. The following groups were tested: Group 1: Prototyped ceramic tube, bonded in the central position; Group 2: Prototyped ceramic tube, bonded in the distal position; Group 3: Simple metallic tube bonded in the central position and Group 4: Simple metallic tube bonded in the distal position. For the execution of the tests, upper left hemiarchs containing from central incisor teeth superior to the upper left second molar were obtained using an STL (Standard Triangle Language) file using the American software Autodesk Meshmixer. The orthodontic tubes were fixed by indirect bonding with cyanoacrylate on the buccal surface of the teeth. To evaluate the efficiency of orthodontic tubes in correcting the rotation of the upper first molar, it was necessary to use an electronic simulator, with the aim of standardizing the tests for all samples researched. Student's T and Mann-Whitney tests were applied to evaluate statistical differences between the results obtained in the groups. In the Central position, the average correction pulses for the prototyped ceramic tubes (39.41 pulses) were higher than the average for the metallic tubes (27.37 pulses) (Student's T test p<0.05). In the distal position, the average correction pulses for the prototyped ceramic tubes (38.38 pulses) were higher than the average for the metallic tubes (18.07 pulses) (Mann-Whitney test, p<0.05). Prototyped ceramic tubes obtained a greater intensity of correction of upper molar rotation than metallic tubes, through the methodology adopted in the present research, in the two situations evaluated. (AU)

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O objetivo da pesquisa foi avaliar a preferência de jovens universitários de cursos das áreas da Saúde, Exatas e Humanas por diferentes modelos de aparelho ortodôntico. Foram selecionados dois (modelos) indivíduos jovens, um masculino e um feminino. Em seguida, foram confeccionadas 6 imagens simulando aparelhos ortodônticos para cada modelo. Após confeccionar um álbum de fotografias com todas as imagens, os álbuns foram entregues aos estudantes universitários (n=169) com idades entre 18 a 25 anos, juntamente com um questionário. Foram então formados 3 grupos de avaliadores das áreas do conhecimento, Saúde (n=62), Exatas (n=51) e Humanas (n=56). No questionário, os avaliadores identificaram o aparelho de sua preferência, caso fossem ser tratados, apontando nas 6 imagens a ordem de sua preferência. Eles ainda responderam o motivo da escolha daquele modelo de aparelho. Os alinhadores obtiveram maiores avaliações sobre os aparelhos estéticos (5,0). Em contrapartida, os aparelhos metálicos foram os piores avaliados (2,0). Não houve influência da área de estudo e do gênero do avaliador sobre a hierarquia de atratividade na avaliação, no entanto as avaliadoras do sexo feminino da área de Saúde foram mais críticas quanto ao aparelho metálico com ligadura azul. Apesar da área de estudo não ter influenciado na preferência pelo tipo de aparelho, sendo os mais estéticos preferidos sobre os metálicos, as avaliações mais críticas partiram dos estudantes da área de Saúde. (AU)

The aim of the present research was to evaluate the preference of young university students from courses of the health, science, and human areas regarding different orthodontic appliance design. Two (models) young individuals were selected, one male and one female. Then 6 images were made simulating orthodontic appliances for each model. After producing a photo album with all the images, the albums have been given to university students (n=169) aged between 18 and 25 years old, along with a questionnaire. Three groups of evaluators from different areas of knowledge: Health (n=62), Science (n=51) an Human area (n=56) were formed. In the questionnaire, the evaluators identified which device they would prefer if they were treated, indicating the order of their preference on the 6 images. They also answered the reason for choosing that device model. Aligners had higher ratings than aesthetic devices (5.0). On the other hand, metallic appliances were the worst evaluated (2.0). There was no influence of the study area and the evaluator's gender on the hierarchy of attractiveness in the evaluation, however female evaluators from the Health area were more critical regarding metallic braces with blue ligature. Although the study area did not influence the preference for the type of appliance, with the most aesthetic being preferred over metallic ones, the most critical evaluations came from students in the Health area (AU)

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Este estudo teve como objetivo avaliar a capacidade de retenção que os attachments proporcionam aos alinhadores ortodônticos, bem como analisar a reprodutibilidade dos attachments a partir do planejamento digital até a sua reprodução clínica. A amostra foi composta por dezesseis modelos, divididos em 2 grupos, sendo oito no grupo controle impresso (GCI), onde os attachments eram impressos no modelo e outros oito modelos no grupo experimental de resina (GER), cujos attachments foram colados manualmente a partir de uma guia de transferência. Cada grupo foi dividido em outros 4 subgrupos, de acordo com o posicionamento dos attachments em determinados dentes e orientação do tal acessório no formato retangular: canino a 2º pré-molar horizontal (HPM), canino a 1º molar horizontal (HM), canino a 2º pré-molar vertical (VPM) e canino a 1º molar vertical (VM). Placas de PETG foram termoformados para um total de 80 alinhadores, sendo 40 para o grupo GCI e outros 40 para o grupo GER nas espessuras de 0.6 mm e 0.8 mm. Os modelos dos grupos GCI e GER foram escaneados e analisados por comparação digital para avaliação da morfologia dos attachments. Em seguida, os alinhadores foram submetidos a ensaio mecânico de tração. A análise qualitativa mostrou que as bases dos attachments colados possuem excesso de resina, dificultando a criação de ângulos vivos. Ao analisar qualitativamente a morfologia do grupo GER foi possível verificar que os attachments colados tiveram suas bases em dimensões maiores que o planejado. O grupo GER apresentou melhores retenções que os grupo GCI. Não há diferença estatística na orientação do acessório e no número de dentes que possuem os dispositivos. Entretanto, há diferença estatística quanto à espessura de PETG onde as placas de 0.8 mm forneceram maior retenção. Neste caso, os attachments horizontais com colagem até os molares apresentam a maior média de retenção estatisticamente significante (p < 0.01) quando comparados aos outros attachments no grupo experimental. Conclui-se que as placas de 0.8 mm conferem retenção superior do que as de espessura 0.6 mm, e também que a combinação de attachments na horizontal com colagem de canino a molar proporcionam maior retenção quando comparados à outra orientação e ao número de dentes envolvidos. (AU)

This study aimed to evaluate the retention capacity that attachments provide to orthodontic aligners, as well as to analyze the reproducibility of attachments made from guides made for this purpose. The sample consisted on sixteen models which were divided into 2 groups, eight in the printed control group (PCG), whose attachments were printed onto the model and eight in the experimental resin group (ERG), whose attachments were bonded manually from transfer guide. Each group was subdivided into 4, according to the positioning and orientation of the attachments: horizontal premolar (HPM), horizontal molar (HM), vertical premolar (VPM) and vertical molar (VM). PETG acetate aligners were thermoformed for a total of 80 aligners, 40 for the PCG group and another 40 for the ERG group in thicknesses of 0.6 mm and 0.8 mm. The models of the PCG and ERG groups were scanned and analyzed by digital comparison to assess the morphology of the attachments. Then, the aligners were subjected to mechanical tensile testing. The qualitative analysis showed that the bases of the bonded attachments have excess resin, making it difficult to create sharp angles. When analyzing the morphology of the ERG group, it was possible to verify they had the bases in larger dimensions than planned. The ERG group had better retentions than the PCG group. There is no statistical difference in the orientation of the accessory and in the number of teeth that the devices have when the attachments are grouped. However, a statistical difference occurs regarding the observed thickness of acetate whose 0.8 mm aligners provided greater retention. In this case, the horizontal attachments with bonding up to the molars have the highest statistically significant retention average (p <0.01) when compared to the other attachments in the experimental group. It is concluded that the 0.8 mm aligners provide superior retention than those of 0.6 mm thickness, and also that the combination of horizontal attachments with molar canine bonding provides greater retention when compared to the other orientation and the number of teeth involved. (AU)

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INTRODUÇÃO: Os aparelhos intraorais (AIO) possuem indicação para tratamento da Síndrome da Apneia Obstrutiva do Sono (SAOS) inclusive em pacientes com baixa adesão ao CPAP. A polissonografia com o AIO pode confirmar benefício terapêutico. MÉTODOS: Compararam-se os resultados polissonográficos de um AIO semiflexível em pacientes sob uso inadequado do CPAP por meio de estudo-piloto retrospectivo, incluindo 17 pacientes (11 homens e 6 mulheres) com 53,7 +- 7,8 anos, IMC de 27,5 +- 4,1kg/m2 e índice de apneia- -hipopneia basal (IAH) de 35,0 +- 19,8/h. Confirmados o uso inadequado ou recusa do CPAP, os pacientes receberam um aparelho com propulsão semiflexível (A-QUALITY) e, após titulação completa, novas polissonografias foram comparadas aos registros basais e com CPAP. Utilizou-se ANOVA para medidas repetidas e post-hoc Bonferroni (p < 0,05). RESULTADOS: Houve redução semelhante no IAH com AIO (7,7 +- 1,7/h) e CPAP (6,1 +- 1,6/h), ambos comparados ao basal (p < 0,001). O índice de dessaturação de O2 foi reduzido com AIO (2,4 +- 0,6/h) e CPAP (1,3 +- 0,6/h), ambos comparados ao basal (15,7 +- 3,8), (p <0,001). O índice de despertares também foi minimizado com AIO (7,2 +- 1,9/h) e CPAP (4,2 +- 0,7/h), ambos comparados ao basal (18,9 +- 5,3), (p<0,001). A eficiência do sono foi maior com o AIO comparado ao CPAP (87,2 +- 2,1 x 75,6 +- 3,9) (p<0,05). CONCLUSÃO: O tratamento com o aparelho selecionado resultou em melhora nos registros polissonográficos nessa amostra e pode ser indicado como alternativa ao CPAP em pacientes subtratados (AU)

INTRODUCTION: Intraoral appliances (IOA) are indicated for treatment of Obstructive Sleep Apnea Syndrome (OSAS) even in patients with poor adherence to CPAP. Polysomnography with IOA may confirm therapeutic benefit. METHODS: Polysomnographic results of a semiflexible IOA in patients under inadequate use of CPAP were compared by a retrospective pilot study including 17 patients (11 men and 6 women) aged 53.7 +- 7.8 years, BMI of 27.05 +- 4.1kg/m2 and basal apnea-hypopnea index (AHI) of 35.0 +- 19.8/h. Confirmed the inappropriate use or refusal of CPAP, the patients received a semiflexible propulsion device (AQUALITY) and, after complete titration, new polysomnographies were compared to baseline and CPAP registers. ANOVA was used for repeated and post-hoc Bonferroni measurements (p <0.05). RESULTS: There was a similar reduction in AHI with OA (7.7 +- 1.7/h) and CPAP (6.1 +- 1.6/h), both compared to baseline (p <0.001). The O2 desaturation index was reduced with IOA (2.4 +- 0.6 h) and CPAP (1.3 +- 0.6/h), both compared to baseline (15.7 +- 3.8) (p <0.001). Awakening rates were also minimized with IOA (7.2 +- 1.9/h) and CPAP (4.2 +- 0.7/h), both compared to baseline (18.9 +- 5.3) (p <0.001). Sleep efficiency was higher with IOA compared to CPAP (87,2 +- 2,1 x 75,6 +- 3,9) (p <0.05). CONCLUSION: Treatment with the selected device resulted in improved polysomnographic records in this sample and may be indicated as an alternative to CPAP in undertreated patients. (AU)

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ABSTRACT Objective: This study aimed at comparing the dentoskeletal changes in patients with Class II division 1 malocclusion, treated with three types of fixed functional appliances. Methods: A sample comprising 95 patients with the same malocclusion, retrospectively selected, and divided into four groups, was used: G1 consisted of 25 patients (mean age 12.77 ± 1.24 years) treated with Jasper Jumper appliance; G2, with 25 patients (mean age 12.58 ± 1.65 years) treated with the Herbst appliance; G3, with 23 patients (mean age 12.37 ± 1.72 years) treated with the Mandibular Protraction Appliance (MPA); and a Control Group (CG) comprised of 22 untreated subjects (mean age 12.66 ± 1.12 years). Intergroup comparison was performed with ANOVA, followed by Tukey test. Results: The Jasper Jumper and the Herbst group showed significantly greater maxillary anterior displacement restriction. The Jasper Jumper demonstrated significantly greater increase in the mandibular plane angle, as compared to the control group. The MPA group demonstrated significantly greater palatal inclination of the maxillary incisors. Vertical development of the maxillary molars was significantly greater in the Herbst group. Conclusions: Despite some intergroup differences in the amount of dentoskeletal changes, the appliances were effective in correcting the main features of Class II malocclusions.

RESUMO Objetivo: o objetivo do presente estudo foi comparar as alterações dentoesqueléticas em pacientes com má oclusão de Classe II, divisão 1, tratados com três tipos de aparelhos funcionais fixos. Métodos: a amostra compreendeu 95 pacientes, selecionados retrospectivamente e divididos em quatro grupos: G1, composto por 25 pacientes (idade média de 12,77 ± 1,24 anos), tratados com aparelho Jasper Jumper; G2, com 25 pacientes (idade média de 12,58 ± 1,65 anos), tratados com aparelho Herbst; G3, com 23 pacientes (idade média de 12,37 ± 1,72 anos), tratados com o Aparelho de Protração Mandibular (APM); e um Grupo Controle (GC), composto por 22 sujeitos não tratados (idade média de 12,66 ± 1,12 anos) que apresentavam a mesma má oclusão. A comparação intergrupos foi realizada com ANOVA, seguida do teste Tukey. Resultados: os grupos Jasper Jumper e Herbst apresentaram significativamente maior restrição de deslocamento anterior da maxila. O Jasper Jumper demonstrou aumento significativamente maior no ângulo do plano mandibular, em comparação ao grupo controle. O grupo APM demonstrou inclinação palatina significativamente maior dos incisivos superiores. O desenvolvimento vertical dos molares superiores foi significativamente maior no grupo Herbst. Conclusões: apesar de algumas diferenças intergrupos na quantidade de alterações dentoesqueléticas, os aparelhos foram eficazes na correção das principais características das más oclusões de Classe II.

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Aim: The aim of this study was to verify the frictional force during sliding mechanics in orthodontic tooth movement, using conventional metal brackets of the active and passive self-ligating types with stainless steel and copper nickel titanium archwires. Methods: This experimental in vitro study was conducted with conventional metal (Morelli, Sorocaba, SP, Brazil) brackets, active self-ligated (SLI Morelli, Sorocaba, SP, Brazil) and passive self-ligated (SLP Morelli, Sorocaba, SP, Brazil), with slot 0.022 x 0.028 inches and Roth prescription. The brackets were tested with rectangular section 0.019 x 0.025 inch copper nickel titanium and stainless steel archwires. For each type of bracket, 10 sets of plate/bracket/archwire segment (n=10) were fabricated. Non-parametric Kruskal Wallis and Dunn tests were used for comparison between types of brackets and Wilcoxon tests for comparison between types of archwires. Results: The results showed that the frictional force values were higher with copper nickel titanium than with stainless steel archwires (p<0.05). When copper nickel titanium archwires were used, the active self-ligating brackets showed higher frictional force values than the other types, followed by the conventional brackets. Lower frictional force values were observed with passive self-ligating brackets. For stainless steel archwires, no difference was observed between conventional and active self-ligating brackets, the passive self-ligating type presented lower frictional force values than the others. Conclusion: It was concluded that the higher frictional force was observed when active self-ligating brackets were associated with copper nickel titanium archwires. Lower frictional force was verified between passive self-ligating brackets combined with stainless steel archwires

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Abstract The aim of this study was to assess, correlate, and compare users' perceptions and preference related to maxillary removable retainers. Volunteers were recruited to use four retainer types: conventional wrap-around (CWA), wrap-around with an anterior opening (OWA), "U" wrap-around (UWA), and clear thermoplastic retainer (CT). The main outcomes were the volunteers' perceptions, evaluated with a 100-mm visual analogue scale, and their preferred retainer. The retainers were used for 21 days each (washout intervals of 7 days). Nineteen volunteers (27 ± 4.53 years) were randomly divided into four groups that used the four retainers, but with a different sequence. Perceptions were evaluated immediately after the use of each retainer and the preference at the end of the research. Repeated measures ANOVA and Friedman tests with post-hoc Tukey's test (intergroup comparisons), and Pearson and Spearman analyses (correlations between perceptions) were applied. The WA retainers did not significantly differ among themselves. The CT was rated significantly worse in speech (p ≤ 0.001), discomfort (p < 0.001), and occlusal interference (p < 0.001), and did not significantly differ from the others in esthetics. Users preferred significant more the WA retainers in comparison with the CT retainers. The occlusal interference caused by the CT was positively correlated to other perceptions, such as changes in speech and discomfort. WA retainers presented similar preference and perceptions, but were significantly better than the CT. The CT occlusal coverage appeared to be the primary cause of its rejection.

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ABSTRACT Introduction: The T-loop as designed by Burstone is a space closure spring used in the rational application of orthodontic biomechanics. Despite the diversity of studies, there is still no consensus on the optimal parametric characteristics for its conformation. Objective: This study aimed at reviewing the literature on the force systems released by different conformations of the T-loop, according to the type of anchorage and the main characteristics and factors that influence them. Results: Comparing the studies, the need for standardization was perceived in the methodology to shape the loops, regarding the variables that influence the force system. Most of the experimental studies with this loop do not report the vertical movement, nor the steps and angles that occur in the brackets. Clinical studies have obtained more variable results in relation to vertical acting forces, considering the influence of chewing. Conclusion: There is great potential for future studies with this type of loop, especially using nickel-titanium alloys, in order to achieve a pure translational movement without friction, with optimal and constant levels of force.

RESUMO Introdução: a alça T preconizada por Burstone é um instrumento de fechamento de espaços utilizado na aplicação racional da biomecânica ortodôntica, dentro da técnica do arco segmentado. Apesar da diversidade de estudos, ainda não há consenso quanto às características paramétricas ótimas para a sua conformação. Objetivo: esse estudo teve como objetivo revisar a literatura sobre os sistemas de forças liberados por diferentes conformações da alça T, de acordo com o tipo de ancoragem necessária, salientando suas principais características e os fatores que as influenciam. Resultados: comparando-se os estudos, foi perceptível a necessidade de padronização da metodologia usada para conformar as alças, levando em consideração as variáveis que exercem influência no sistema de forças, de forma a se obter sistemas mais acurados, permitindo a realização de testes mais precisos e uma comparação mais eficaz dos estudos. A maioria dos estudos experimentais com esse tipo de alça não relata a movimentação vertical, nem os degraus e ângulos que ocorrem nos braquetes. Estudos clínicos obtiveram resultados menos rígidos em relação às forças verticais atuantes, levando em consideração a influência da mastigação. Conclusões: há grande potencial para futuros estudos com esse tipo de alça, especialmente utilizando ligas de níquel-titânio, para que se chegue cada vez mais perto de um movimento de translação puro e sem atrito, com níveis de força ótimos e constantes.

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Aproximadamente um terço dos pacientes com atresia maxilar apresenta uma constrição mais acentuada da distância intercaninos, quando comparada à distância intermolares superiores. Nesses casos, uma quantidade de expansão individualizada é requerida nas regiões anterior e posterior do arco dentário a fim de prevenir a sobre-expansão na região dos pré-molares e molares, redundando num risco aumentado de deiscências ou fenestrações ósseas vestibulares. Uma alternativa clínica para a correção transversal, nesses casos, é a utilização do Expansor Maxilar Diferencial (EMD). Esse aparelho ortopédico com dois parafusos permite realizar uma expansão diferencial significantemente maior na região anterior, quando comparada à região posterior do arco dentário superior. O objetivo deste artigo é relatar um caso clínico de uma paciente do sexo feminino, na dentadura permanente jovem, com mordida cruzada posterior, tratada de forma individualizada e eficiente com o EMD. (AU)

Approximately one third of patients with maxillary atresia show greater constriction of intercanine distance compared to the intermolar distance. In these cases, an individualized amount of expansion is required in the anterior and posterior regions of the dental arch, in order to prevent overexpansion in the premolar and molar region, resulting in increased risk of dehiscence or bone fenestration. A clinical alternative for transverse correction in these cases is the Differential Maxillary Expander (DME). This orthopedic expander with two screws allows accomplishing a significantly greater differential expansion in the anterior region compared to the posterior region of the maxillary dental arch. The aim of this article is to report a clinical case of a female patient in the early permanent dentition with posterior crossbite that was individually and efficiently treated using the DME.(AU)

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OBJECTIVES: This retrospective study aimed to evaluate the dentoalveolar, skeletal, and soft tissue effects obtained with bone-anchored pendulum appliance in patients with Class II malocclusion. MATERIALS AND METHODS: A total of 18 patients (4 male, 14 female) at a mean pretreatment age of 14.0 years (+1.08) were enrolled in this study. All patients were treated with the bone-anchored pendulum appliance for an average duration of 4.8 months. Only the active distalization period was evaluated with predistalization and postdistalization lateral cephalograms. Skeletal, dentoalveolar, and soft tissue variables were obtained. Based on these variables, the treatment effects were evaluated with dependent t-test. RESULTS: Correction of Class II molar relationship resulted from distal movement of 3.45 mm and tipping of 11.24° of the first maxillary molars. The premolars were distalized accompanying the molars. CONCLUSIONS: The bone-anchored pendulum appliance proved to be an effective method for distalization of maxillary molars in cases that require maximum anchorage, avoiding reciprocal mesial movement of premolars and incisors.

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Introdução: O aparelho ortopédico mecânico Herbst destaca-se entre os aparelhos que estimulam o avanço mandibular. Objetivo: Esse artigo demonstra diferentes formas de ancoragem para o aparelho Herbst. Método: Descrevem-se formas distintas de ancoragem, variando desde ancoragem com banda ortodôntica, com esplinte acrílico, com esplinte metálico, associadas ou não ao parafuso expansor. Conclusão: A escolha do tipo de ancoragem para o aparelho Herbst é dependente do plano de tratamento ortodôntico e definida de forma individual para cada paciente.

Introduction: Herbst mechanical orthopedic device stands out among the devices that stimulate the mandibular advancement. Objective: This paper describes different forms of Herbst appliance anchorage. Method: Distinct forms of Herbst appliance anchorage are described varying from orthodontic band, acrylic splint, metallic splint ancorage associated or not with expansion screw. Conclusions: The choice of Herbst appliance anchorage is dependent of orthodontic treatment planning and defined individually for each patient.

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OBJECTIVES: The aims were to evaluate the levels of bacterial species in saliva and in situ and to assess whether the design of brackets influences the risk of developing periodontal disease. MATERIALS AND METHODS: Twenty patients (13.3 mean age) were bonded with self-ligating brackets and a conventional bracket. Saliva was collected before bonding and 30 and 60 days after bonding. One sample of each bracket was removed 30 and 60 days after bonding. The analysis was determined by checkerboard DNA-DNA hybridization. The data was evaluated by the non-parametric test. RESULTS: A significant increase in the levels of bacterial species in the saliva occurred in 15 of the 22 analyzed species. The self-ligating brackets presented the highest incidence percentages for the orange and red complexes 60 days after bonding. In situ analyses showed different patterns according to the bracket design. The levels of Campylobacter rectus showed significant differences (p = 0.011) 60 days after bonding among the three brackets; the highest values were observed in the In-Ovation®R bracket. CONCLUSIONS: The bracket design seems to influence the levels of bacterial species involved in periodontal disease. Considering the wide variety of bacterial species, additional studies are needed to aid in the establishment of effective protocols to prevent the development of periodontal disease during orthodontic treatment. CLINICAL RELEVANCE: A dynamic alteration in the oral microbiota may lead to inflammatory reactions in the supporting soft and hard tissues. The different types of brackets interfere with bacterial adherence. Bracket design should be considered in orthodontic treatment.

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Abstract The objective of this study was to compare coating dimensions and surface characteristics of two different esthetic covered nickel-titanium orthodontic rectangular archwires, as-received from the manufacturer and after oral exposure. The study was designed for comparative purposes. Both archwires, as-received from the manufacturer, were observed using a stereomicroscope to measure coating thickness and inner metallic dimensions. The wires were also exposed to oral environment in 11 orthodontic active patients for 21 days. After removing the samples, stereomicroscopy images were captured, coating loss was measured and its percentage was calculated. Three segments of each wire (one as-received and two after oral exposure) were observed using scanning electron microscopy for a qualitative analysis of the labial surface of the wires. The Lilliefors test and independent t-test were applied to verify normality of data and statistical differences between wires, respectively. The significance level adopted was 0.05. The results showed that the differences between the wires while comparing inner height and thickness were statistically significant (p < 0.0001). In average, the most recently launched wire presented a coating thickness twice that of the control wire, which was also a statistically significant difference. The coating loss percentage was also statistically different (p = 0.0346) when the latest launched wire (13.27%) was compared to the control (29.63%). In conclusion, the coating of the most recent wire was thicker and more uniform, whereas the control had a thinner coating on the edges. After oral exposure, both tested wires presented coating loss, but the most recently launched wire exhibited better results.

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ABSTRACT Introduction: Skeletal Class III malocclusion is often referred for orthodontic treatment combined with orthognathic surgery. However, with the aid of miniplates, some moderate discrepancies become feasible to be treated without surgery. Objective: To report the case of a 24-year-old man with severe skeletal Angle Class III malocclusion with anterior crossbite and a consequent concave facial profile. Methods: The patient refused to undergo orthognathic surgery; therefore, orthodontic camouflage treatment with the aid of miniplates placed on the mandibular arch was proposed. Results: After 18 months of treatment, a Class I molar and canine relationship was achieved, while anterior crossbite was corrected by retraction of mandibular teeth. The consequent decrease in lower lip fullness and increased exposure of maxillary incisors at smiling resulted in a remarkable improvement of patient's facial profile, in addition to an esthetically pleasing smile, respectively. One year later, follow-up revealed good stability of results.

RESUMO Introdução: a má oclusão de Classe III esquelética é frequentemente tratada com associação entre Ortodontia e Cirurgia Ortognática. No entanto, com o auxílio das miniplacas, discrepâncias moderadas tornaram-se passíveis de serem tratadas sem a necessidade de cirurgia ortognática. Objetivo: relatar o caso de um paciente de 24 anos, com má oclusão de Classe de III Angle e Classe III esquelética, mordida cruzada anterior e consequente perfil facial côncavo. Métodos: o paciente recusou-se a realizar a cirurgia ortognática, assim, foi proposta a compensação da má oclusão com o auxílio de miniplacas na arcada inferior. Resultados: após 18 meses de tratamento, foram obtidas relações de molares e caninos em Classe I, e a mordida cruzada anterior foi corrigida, por meio da distalização de todos os dentes inferiores. A consequente redução na projeção do lábio inferior, associada à maior exposição dos incisivos superiores no sorriso, resultou em um perfil facial consideravelmente mais agradável e um sorriso esteticamente melhor, respectivamente. A análise um ano após o tratamento revelou boa estabilidade dos resultados obtidos.

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ABSTRACT Introduction: A canted occlusal plane presents an unesthetic element of the smile. The correction of this asymmetry has been typically considered difficult by orthodontists, as it requires complex mechanics and may sometimes even require orthognathic surgery. Objective: This paper outlines the case of a 29-year-old woman with Class II malocclusion, pronounced midline deviation and accentuated occlusal plane inclination caused by mandibular deciduous molar ankylosis. Methods: The patient was treated with a miniplate used to provide anchorage in order to intrude maxillary teeth and extrude mandibular teeth on one side, thus eliminating asymmetry. Class II was corrected on the left side by means of distalization, anchored in the miniplate as well. On the right side, maxillary first premolar was extracted and molar relationship was kept in Class II, while canines were moved to Class I relationship. The patient received implant-prosthetic rehabilitation for maxillary left lateral incisor and mandibular left second premolar. Results: At the end of treatment, Class II was corrected, midlines were matched and the canted occlusal plane was totally corrected, thereby improving smile function and esthetics.

RESUMO Introdução: o plano oclusal inclinado representa um elemento antiestético para o sorriso. A correção dessa assimetria é normalmente considerada difícil pelos ortodontistas, requerendo mecânica complexa e, algumas vezes, até cirurgia ortognática. Objetivo: esse artigo descreve o caso de uma paciente de 29 anos, portadora de má oclusão de Classe II, com considerável desvio das linhas médias e acentuada inclinação do plano oclusal, causada pela anquilose de molar decíduo inferior. Métodos: a paciente foi tratada com ancoragem em miniplaca, para promover a intrusão dos dentes superiores e extrusão dos dentes inferiores em um lado, eliminando a assimetria. A Classe II foi corrigida no lado esquerdo por meio de distalização, também ancorada na miniplaca. No lado direito, o primeiro pré-molar superior foi extraído e a relação de molares de Classe II foi mantida, enquanto os caninos foram movidos para relação de Classe I. A paciente recebeu reabilitação por meio de implante e prótese no incisivo lateral superior esquerdo e no segundo pré-molar inferior esquerdo. Resultados: ao término do tratamento, a Classe II foi corrigida, as linhas médias estavam coincidentes e a inclinação do plano oclusal foi totalmente corrigida, melhorando consideravelmente os aspectos funcionais e estéticos da oclusão.

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Aim: To evaluate the prevalence and hygiene habits of 13-19 years-old adolescent users of removableorthodontic appliances (ROA) and to determine hygiene methods for the appliances prescribed bydentists, in the city of Pelotas. Methods: The study had two stages. The first stage was a telephoneinterview with dentists. Dentists were interview by telephone calls in order to obtain informationregarding the hygiene methods for cleaning acrylic appliances. Second stage was a cross-sectionalstudy performed with schoolchildren. Children from public and private schools with secondary levelwere included in the sample. A questionnaire was applied to the students using any type of ROA.Questionnaires included demographic information and behavioral characteristics. Data collectedwere subjected to Chi-square test and logistic regression. Results: The prevalence of children usingROA was 5.4%. Students (89.7%) and dentists (47.2%) reported to prefer mechanical methods toclean their ROA. Cleaning with soup, hydrogen peroxide or effervescent tabs were less used. Highfrequency of use was associated with higher frequency of hygiene on the ROA. Conclusions: Theprevalence of schoolchildren using removable appliances was low. The common cleaning methodused by children and prescribed by dentists was mechanical. Hygiene frequency was significantlyassociated with the routine of use of the appliance and with the type of hygiene method.

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Introdução: O objetivo do presente trabalho foi comparar os efeitos dentoesqueléticos do expansor com abertura diferencial (EAD) e do expansor Hyrax convencional em crianças na dentadura mista. Métodos: Quarenta e seis pacientes de ambos os sexos e com idades variando de 7 a 11 anos foram aleatoriamente alocados em um de dois grupos de estudo. O grupo experimental foi composto por 22 pacientes (idade média de 8,46 anos) que foram submetidos à expansão rápida da maxila (ERM) com o EAD. O grupo de comparação foi composto por 24 pacientes (idade média de 8,92) tratados com ERM utilizando-se o expansor Hyrax convencional. Fotografias foram obtidas imediatamente antes da expansão (T1) e ao término do período ativo da expansão maxilar (T2). Radiografias oclusais da maxila foram obtidas para cada paciente apenas ao término do período ativo da expansão maxilar (T2). Modelos digitais dos arcos dentários superior e inferior foram obtidos imediatamente antes da expansão (T1) e 6 meses pós-expansão (T3), na ocasião da remoção do aparelho. As variáveis de desfecho primário foram as alterações no diastema interincisal, a quantidade de abertura da sutura palatina mediana, as larguras dos arcos dentários superior e inferior, o perímetro dos arcos, o comprimento dos arcos, a profundidade do palato, a inclinação dos dentes pósterossuperiores e pósteroinferiores e a forma do arco dentário superior. A variável de desfecho secundário foi a quantidade de expansão diferencial nas regiões anterior e posterior do arco dentário superior. As comparações interfases e intergrupos foram realizadas por meio dos testes t pareado e testes t, respectivamente, com correção de Bonferroni para testes múltiplos. Resultados: Tanto o EAD quanto o expansor Hyrax convencional promoveram aumentos significantes do diastema interincisivos e da largura do arco dentário superior. Por outro lado, nenhuma diferença significante foi observada para a largura do arco dentário inferior de ambos os grupos de estudo. O EAD promoveu um aumento significante do perímetro do arco dentário superior e uma diminuição significante da profundidade do palato. De modo contrário, não foram observadas diferenças significantes para o perímetro do arco dentário inferior de nenhum dos dois grupos estudados. O comprimento do arco dentário superior diminuiu significantemente após a ERM com o expansor Hyrax, enquanto que o comprimento do arco inferior diminuiu suavemente no grupo do EAD. Ambos os expansores promoveram um aumento significante da inclinação vestibular dos dentes pósterossuperiores e dos caninos decíduos inferiores. O EAD promoveu aumentos significantemente maiores da dimensão da abertura da sutura palatina mediana, da largura do diastema interincisivos e das distâncias intercaninos, inter-primeiros molares decíduos e intersegundos molares decíduos superiores, quando comparado com o expansor Hyrax. Por outro lado, apenas o grupo de comparação apresentou um suave aumento da distância interprimeiros molares permanentes inferior. O grupo experimental apresentou uma expansão diferencial significantemente maior na região anterior quando comparada à região posterior do arco dentário superior, enquanto que o grupo de comparação promoveu quantidades de expansão similares na região dos caninos e dos primeiros molares permanentes superiores. Conclusões: Na dentadura mista, o expansor com abertura diferencial foi capaz de promover uma disjunção maxilar com uma maior abertura da região anterior da sutura palatina mediana. O EAD promoveu uma maior expansão da região anterior do arco dentário superior quando comparado com o expansor Hyrax convencional. Ambos os expansores se mostraram similares quanto à quantidade de expansão na região posterior do arco dentário superior, e para as alterações do perímetro dos arcos, comprimento dos arcos, profundidade do palato e inclinação dos dentes posteriores. Adicionalmente, pequenas alterações espontâneas do arco dentário inferior foram observadas para ambos os expansores, seis meses após a expansão rápida diferencial e convencional da maxila.(AU)

Introduction: The aim of this study was to compare the dentoskeletal effects of the expander with differential opening (EDO) and the conventional Hyrax expander in children in the mixed dentition. Methods: Forty-six patients of both sex and ages ranging from 7 to 11 years old were randomly allocated into two study groups. The experimental group comprised 22 patients (mean age of 8.46 years) who underwent rapid maxillary expansion (RME) with the EDO. The comparison group comprised 24 participants (mean age of 8.92 years) treated with RME using the conventional Hyrax expander. Photographs were obtained immediately pre-expansion (T1) and at the end of the active expansion phase (T2). Occlusal radiographs of maxilla were obtained for each patient at the end of the active expansion phase only (T2). Digital dental models of the maxillary and mandibular dental arches were obtained immediately preexpansion (T1) and 6 months post-expansion (T3), at the occasion of appliance removal. The primary outcomes were the interincisal diastema width change, the dimension of midpalatal suture opening, the maxillary and mandibular dental arch widths, the arches perimeter, the arches length, the palatal depth, the inclination of maxillary and mandibular posterior teeth and the maxillary dental arch shape. The secondary outcome was the amount of differential expansion in the anterior region compared to the posterior region of maxillary dental arch. Inter-phase and intergroup comparisons were performed using paired t tests and t tests, respectively, with Bonferroni correction for multiple tests. Results: Both the EDO and the conventional Hyrax expander promoted significant increases of the interincisal diastema width and of the maxillary dental arch widths. On the other hand, no significant differences were found for the mandibular dental arch widths of both groups. The EDO promoted a significant increase of the maxillary dental arch perimeter and a significant decrease of the palatal depth. On the other hand, no significant differences were found for the mandibular dental arch perimeter of both study groups. The maxillary dental arch length decreased significantly after RME with the conventional Hyrax expander. On the other hand, the mandibular dental arch length decreased slightly in the EDO group. Both expanders promoted a significant buccal inclination of the maxillary posterior teeth and mandibular deciduous canines. The EDO promoted significantly greater increases of the dimension of midpalatal suture opening, the width of interincisal diastema, the maxillary intercanine distance, the maxillary inter-first deciduous molars distance and the maxillary inter-second deciduous molars distance compared to the Hyrax expander. On the other hand, only the comparison group showed a slight decrease of the mandibular intermolar distance. The experimental group showed a significant differential expansion between the anterior and the posterior regions of the maxillary dental arch while the comparison group produced similar amount of expansion in the maxillary canine and in the maxillary molar regions. Conclusions: In the mixed dentition, the expander with differential opening was capable of producing an intermaxillary split with an increased dimension at the anterior limit of the midpalatal suture. The EDO promoted a greater expansion in the anterior region of the maxillary dental arch compared to the conventional Hyrax expander. Similarity between the two expanders was observed for posterior region expansion and for changes in arch perimeter, arch length, palatal depth and posterior teeth inclination. Additionally, small mandibular spontaneous dentoalveolar changes were observed for both expanders six months after differential and conventional rapid maxillary expansion.(AU)

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